Different kinds of LCDs have been used in a variety of applications. A double-sided LCD includes front and rear LCD panels, which are coupled together back-to-back. The LCD panels used in the double-sided LCD may have the same size or different sizes. In a typical mobile phone, the LCD panels have different sizes. The double-sided LCD further includes a double-sided backlight module disposed between the front and rear LCD panels.
Referring to FIG. 4, a typical double-sided LCD used in a mobile phone is shown. The double-sided LCD 100 includes a light guide plate 130, a light source 140, a first optical film assembly 111, a second optical film assembly 121, a first liquid crystal panel 112, a second liquid crystal panel 122, and a frame 150 for fixing the above components. The light guide plate 130 includes a light incident surface 133, a first light emitting surface 131 perpendicularly connected with the light incident surface 133, and a second light emitting surface 132 opposite to the first light emitting surface 131. The first optical film assembly 111 and the first liquid crystal panel 112 are disposed adjacent to the first light emitting surface 131 of the light guide plate 130, in that order from top to bottom. The second optical film assembly 121 and the second liquid crystal panel 122 are disposed adjacent to the second light emitting surface 132 of the light guide plate 130, in that order from bottom to top. The light guide plate 130, the first optical film assembly 111, the second optical film assembly 121, and the first liquid crystal panel 112 have substantially equivalent areas. An area of the second liquid crystal panel 122 is much less than that of the first liquid crystal panel 112. Generally, the first liquid crystal panel 112 is used as a main display, and the second liquid crystal panel 122 is used as a secondary display.
Light beams emitted from the light source 140 enter the light guide plates 130 through the light incident surface 133. Some of the light beams are then emitted directly from the first and second light emitting surfaces 131, 132. Other of the light beams are emitted from the first and second light emitting surfaces 131, 132 after being reflected one or more times in the light guide plate 130. All light beams emitted from the first and second light emitting surfaces 131, 132 respectively transmit through the first and second optical film assemblies 111, 121 and through the first and second liquid crystal panels 112, 122. Thereby, a double-sided display is achieved.
The first and second optical film assemblies 111, 121 have equivalent areas, yet the second liquid crystal panel 122 has an area much smaller than that of the first liquid crystal panel 112. Thus part of the second optical film assembly 121 is essentially not utilized, while the cost of the double-sided LCD 100 includes the full cost of the second optical film assembly 121.
Therefore, a new double-sided LCD that can overcome the above-described problems is desired.